Patient-specific alignment guide for multiple incisions

ABSTRACT

A patient-specific alignment guide for an orthopedic implant. The alignment guide can include a body having first and second opposing surfaces, the second surface adapted for positioning over a skin surface, and at least one extension extending from the second surface body. The extension has a distal end defining a patient-specific end surface that is mateable in form-fitting manner with a subcutaneous portion of the patient&#39;s anatomy, and at least one guiding passage extending between the first surface of the body and the distal end of the extension.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in part of U.S. application Ser. No. 11/756,057, filed on May 31, 2007, which claims the benefit of U.S. Provisional Application No. 60/812,694, filed on Jun. 9, 2006. This application claims the benefit of U.S. Provisional Application No. 60/953,637, filed on Aug. 2, 2007. The disclosures of the above applications are incorporated herein by reference.

INTRODUCTION

Various custom made, patient-specific orthopedic implants and associated templates and guides are known in the art. Such implants and guides can be developed using commercially available software. Custom implant guides are used to accurately place pins, guide bone cuts, and insert implants during orthopedic procedures. The guides are made from a pre-operative plan formed from an MRI or CT scan of the patient and rely on matching a subcutaneous anatomic feature for correct positioning.

The present teachings provide patient-specific guides for minimally invasive procedures.

SUMMARY

The present teachings provide a patient-specific alignment guide for an orthopedic implant. The patient-specific guide can include a body having first and second opposing surfaces, the second surface adapted for positioning over a skin surface, at least one extension extending from the second surface body, the extension having a distal end, the distal end defining a patient-specific end surface that is mateable in form-fitting manner with a subcutaneous portion of the patient's anatomy, and at least one guiding passage extending between the first surface of the body and the distal end of the extension.

In another aspect, the patient-specific alignment guide can include a body having first and second opposing surfaces, the second surface for positioning over the skin, and a plurality of extensions extending from the body, each extension having a distal end, at least one extension having a distal end defining a patient-specific end surface that is mateable in form-fitting manner with a subcutaneous portion of the patient's anatomy, the at least one extension having a longitudinal passage communicating with the first surface of the body and extending to the distal end of the at least one extension.

The present teachings also provide a method for multiple incision orthopedic surgery. The method includes making a plurality of incisions through the skin of the patient to a plurality of corresponding subcutaneous anatomic portions, supporting a body of an alignment guide outside the incisions, the alignment guide having a plurality of extensions extending from the body of the alignment guide, and percutaneously passing each extension through the corresponding incision, at least one extension having a patient-specific end surface conformable in form-fitting manner with a corresponding subcutaneous anatomic portion. The method further includes mating the end surface of the at least one extension to the corresponding subcutaneous anatomic portion, inserting a tool through a guiding passage extending from the body and along the at least one extension to the distal end surface of the at least one extension, and preparing the corresponding subcutaneous anatomic portion for the surgical procedure.

Further areas of applicability of the present teachings will become apparent from the description provided hereinafter. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is an isometric view of a patient-specific alignment guide according to the present teachings;

FIG. 1A is an environmental view of a patient-specific alignment guide according to the present teachings;

FIG. 2 is an environmental view of a patient-specific alignment guide according to the present teachings;

FIG. 3A is an environmental view of a patient-specific alignment guide according to the present teachings;

FIG. 3B is a view of the patient's anatomy after removal of the alignment guide of FIG. 3A; and

FIG. 4 is an environmental view of a patient-specific alignment guide according to the present teachings.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no way intended to limit the teachings, its application, or uses. For example, although the present teachings are illustrated for specific implant or alignment guides in spinal surgery, the present teachings can be used for other guides, templates, jigs, drills, rasps or other instruments used in various orthopedic procedures.

The present teachings generally provide patient-specific implant guides for use in orthopedic surgery for the knee, hip, shoulder, or spine, for example. The implant guides can be used either with conventional or patient-specific implant components prepared with computer-assisted image methods. Computer modeling for obtaining three dimensional images of the patient's anatomy using MRI or CT scans of the patient's anatomy, the patient specific prosthesis components, and the patient-specific guides and templates can be provided by various CAD programs and/or software available, for example, by Materialise USA, Ann Arbor, Mich.

The guides are generally formed using computer modeling for matching a three-dimensional image of the patient's bone surface (with or without cartilage or other soft tissue), by the methods discussed above. The guides can include custom-made guiding formations, such as, for example, bores or holes that can be used for supporting or guiding other instruments, such as drills, reamers, and cutters, or for inserting pins or other fasteners. The guides can be use in minimally invasive surgery, and in particular in surgery with multiple minimally-invasive incisions. Only portions of the guide are inserted through the incisions, while the main body of the guide remains outside the incisions.

Referring to FIG. 1, a patient-specific alignment guide 100 includes a body 102 having first and second surfaces 106, 108, and one or more extensions 104. Each extension 104 can extend from the body 102 away and spaced apart from the second surface 108, such that the extensions 104 and the second surface define a void or empty space. Each extension 104 can terminate at a distal end 120. Although four substantially parallel extensions 104 are illustrated in FIG. 1, fewer or additional extensions 104 can be included. Each extension 104 can have a different orientation at an angle relative to the other extensions 104 and to the body. The orientation of each extension 104 can be determined based on patient-specific considerations, as discussed below.

Referring to FIG. 1A, the alignment guide 100 can include one or more guiding passages 110, each guiding passage 110 corresponding to one of the extensions 104 and extending from the first surface 106 to the distal end 120 of the corresponding extension 104. The guiding passage 110 can be a longitudinal internal bore. The guiding passage 110 can also be a longitudinal slot or other open channel formed on an outer surface of the extension 104. In one aspect, one or more the guiding passages 110 can be in the form of a cutting slots. Similarly to the extensions 104, the guiding passages 110 can have different orientations, such along axes A, A′, etc, relative to one another and relative to the body 102. The orientations of the extensions 104, the guiding passages 110 and corresponding axes A, A′ can be patient-specific, as determined by the corresponding geometric relationship of subcutaneous anatomic portions 82 of the patient. Similarly, the length of each extension 104 and its corresponding passage 110 can be different, as determined by the relative depths of the subcutaneous anatomic portions 82. In the exemplary alignment guide of FIG. 1A, two extensions 104 with different lengths L and L′ corresponding to different depths d, d′ of the subcutaneous anatomic portions 82 are illustrated. The orientations and locations of the extensions 104 and the corresponding bores 110 can be determined during pre-operative planning of the corresponding surgical procedure. In one aspect, one or more extensions 104 can be pivotably or angulatably coupled to the body 102, such that the orientation A of one or more extensions 104 can be adjusted intra-operatively by the surgeon, as necessary.

The guiding passages 110 can be sized and shaped to receive a tool 200, such as a drill bit of a drilling instrument, or other end tool that can be used for preparing the surgical site, as shown in FIG. 1. The guiding passages 110 can be cylindrical internal bores with variously shaped cross-sections, including circular, triangular, oval, polygonal, slot-like or otherwise shaped. The guiding passages 110 can also be slots or grooves or open channels defined on an outer surface of the corresponding extensions. At least one distal end 120 can define a patient-specific distal end surface or footprint 122 that can conform in a form-fitting manner, mate and nest with a corresponding portion 82 of the patient's anatomy, as illustrated in FIG. 2. The footprint 122 defines a three-dimensional patient-specific contour surface. Additionally, the position, dimensions, distances and orientations of the distal ends 120 relative to one another can be designed during the pre-operative planning procedure to conform or have a nesting surface to nest to a plurality of corresponding portions 82 of the patient's anatomy. The subcutaneous anatomic portions 82 can be bone portions or other subcutaneous tissue accessible by corresponding minimally invasive incisions 88.

In one aspect, each extension 104 can include a guiding passage 110 and a distal end with a patient-specific footprint 122. In another aspect, some of the extensions 104 can be used for stabilizing and anchoring the alignment guide 100 to the patient, and not for passing instruments and/or drilling therethrough. In this respect, such stabilizing extensions 104 may or may not include a guiding passage 110. A stabilizing extension may or may not have a patient-specific footprint 122 at its distal end 120. For example, the distal end 120 of a stabilizing extension 104 can have a tapering or pointed tip for anchoring. An alignment guide 100 having three or more extensions with only one of the extensions 104 having a guiding passage 110 and a patient-specific foot print 122, can be used, for example, in anterior cruciate ligament (ACL) replacement procedure.

As shown in FIG. 1, the extensions 104 can be integrally formed integrally with the body 102, forming one monolithic, one-piece device. In one aspect, and referring to FIG. 1A, one or more extensions 104 can be modular, such that one or more extensions 104 can be added or removed from the body 102 for a particular application. In another aspect, one or more extensions 104 can be telescopically coupled to the body 102, such that the length of the extension 104 or the distance of the distal end 120 from the second surface 108 of the body 102 can be increased or decreased to accommodate variations between similar subcutaneous anatomic features of the patient.

FIGS. 2 and 3 illustrate an exemplary alignment guide 100 for use in a spinal procedure. The alignment guide 100 can be used, for example, to drill holes 84 for fasteners or other implants in adjacent vertebrae of the spine 80. The exemplary alignment guide 100 can include four distal ends 120 that can be used to drill two pairs of holes 84 at corresponding portions 82 of the spine, for inserting pedicle screws or other fasteners for spinal fixation or other spinal procedure. The body 102 of the alignment guide 100 can be positioned with the second surface 108 of the body 102 on an outer surface or the skin 86 of the patient's anatomy outside the incision. Each extension 104 can be percutaneously inserted through a corresponding minimally-invasive incision 88 and positioned in nesting conformance with a subcutaneous portion 82 of the spine for which the patient specific footprint 122 of the extension 104 was specifically designed to nest and conform in a form-fitting manner. After the alignment guide 100 is positioned on the patient's skin 86 and the extensions 104 are percutaneously passed through corresponding incisions, such that each footprint 122 contacts and conforms in a nesting manner to the corresponding subcutaneous anatomic portion 82 of the spine 80, a drill 200 or other instrument can be percutaneously inserted for preparing the subcutaneous anatomic portion 82 to receive a fastener, an implant or a portion of an implant. The alignment guide 100 can be secured on the patient with guide wires or drill bits other temporary fasteners and supporting devices. In one aspect, a guide wire can pass through a guiding passage 110, while another guiding passage is used for drilling.

FIG. 4 illustrates an exemplary alignment guide 100 for use with a long bone 90, such as a femoral bone, for a fracture or other trauma procedure, in which an intramedullary nail 300 having a proximal portion 302 and a distal portion 304 can be implanted. The alignment guide 100 can be used to drill openings for securing first and second locking fasteners 310 transversely through an intramedullary nail 300 from a trochanteric region 92 to the head 96 of the femoral bone 90. The alignment guide 100 can have first and second extensions 104 having length, size and orientation determined such that their corresponding distal ends 120 and foot print surfaces 122 conform to the subcutaneous anatomic portions of the femoral bone 90 at the site of the insertion of the fasteners 310, at the proximal portion 302 of the intramedullary nail 300. Another alignment guide 100 can be used, for example, for drilling openings for fasteners 310 passing through the distal portion 304 of the intramedullary nail 300, and adapted for that bone location.

It will be appreciated that other guides can be similarly constructed for guiding and preparing other bones or bone joints for receiving prosthetic components or fixation pins or other fasteners, or for securing bone plates for fractures and other defects. Patient-specific alignment guides 100 can be constructed, for example, for various portions of the spine, the wrist, long bones of the extremities, as well as for various bone regions associated with joints, such as the knee, the hip, the shoulder, etc. The patient-specific alignment guides 100 can include one or more guiding passages 110 along extensions 104 that pass through minimally-invasive incisions and have patient-specific foot prints that conform and nestingly mate with corresponding subcutaneous anatomic portions of a specific patient. It will be appreciated that the subcutaneous anatomic portions 82 can include bone tissue or soft tissue associated with underlying bone tissue. The body 102 of the alignment guide 100 and access to the guiding passages 110 can remain outside the incisions 88, such that the incision size can be reduced, and the various tools and alignment guides 100 can be easily manipulated by the surgeon outside the incisions.

The foregoing discussion discloses and describes merely exemplary arrangements of the present teachings. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings that various changes, modifications and variations can be made therein without departing from the spirit and scope of the teachings as described herein. 

1. A method for multiple incision orthopedic surgery comprising: making a plurality of incisions through the skin of the patient to a plurality of corresponding subcutaneous anatomic portions; supporting an undersurface of a body of an alignment guide on an outer skin surface of the patient, the alignment guide having a plurality of extensions extending from the undersurface of the alignment guide, wherein at least one extension has a patient-specific distal end surface preoperatively configured from a three-dimensional image of the patient's anatomy to nestingly mate and conform in form-fitting manner with a corresponding subcutaneous anatomic portion; percutaneously passing each extension through the corresponding incision; contacting the patient-specific distal end surface of the at least one extension to the corresponding subcutaneous anatomic portion; inserting a tool through a guiding passage extending from the body and along the at least one extension to the distal end surface of the at least one extension; and preparing the corresponding subcutaneous anatomic portion for the surgical procedure using the tool.
 2. The method of claim 1, wherein preparing the corresponding subcutaneous anatomic portion for the surgical procedure comprises drilling a hole through the subcutaneous anatomic portion.
 3. The method of claim 1, wherein the subcutaneous anatomic portions are vertebral portions.
 4. The method of claim 1, wherein the subcutaneous anatomic portions are portions of a long bone.
 5. The method of claim 1, wherein mating the end surface of the at least one extension to the corresponding subcutaneous anatomic portion, includes telescopically moving the at least one extension to the subcutaneous anatomic portion.
 6. The method of claim 1, wherein mating the patient-specific distal end surface of the at least one extension to the corresponding subcutaneous anatomic portion includes pivoting the at least one extension toward the subcutaneous anatomic portion. 